Transmission systems to control heat exchangers to manage transmission sump temperature

ABSTRACT

Transmission systems, control systems for vehicles, and methods of operating vehicles are disclosed herein. A transmission system for a vehicle includes a transmission and a heat exchanger. The transmission is configured to receive rotational power supplied by a drive unit and provide the rotational power to a load in use of the transmission system. The heat exchanger is fluidly coupled to the transmission and configured to cool a sump of the transmission to manage transmission oil temperature in use of the transmission system. The transmission includes a control system having a plurality of sensors and a controller coupled to the plurality of sensors that has a processor and a memory device coupled to the processor.

FIELD OF THE DISCLOSURE

The present disclosure relates, generally, to transmission systems, and,more specifically, to transmission systems incorporating one or moreheat exchangers.

BACKGROUND

Heat exchangers may be used to cool oil stored in transmission sumps tomanage sump temperature in use of the transmissions. In someapplications, cooling systems incorporating such heat exchangers mayprovide, or otherwise be associated with, excessive cost and/orcomplexity, as well as limited performance. Systems and/or devices toimprove cooling system performance that avoid the aforementionedshortcomings remain an area of interest.

SUMMARY

The present disclosure may comprise one or more of the followingfeatures and combinations thereof.

According to one aspect of the present disclosure, a transmission systemfor a vehicle may include a transmission and a heat exchanger. Thetransmission may be configured to receive rotational power supplied by adrive unit and provide the rotational power to a load in use of thetransmission system. The heat exchanger may be fluidly coupled to thetransmission and configured to cool a sump of the transmission to managetransmission oil temperature in use of the transmission system. Thetransmission may include a control system having a plurality of sensorsand a controller coupled to the plurality of sensors that has aprocessor and a memory device coupled to the processor. At least one ofthe plurality of sensors may be configured to provide sensor dataindicative of a state of a braking device of the vehicle or a faultstate of the vehicle. The memory device may have instructions storedtherein that are executable by the processor to cause the processor toreceive the sensor data from the at least one of the plurality ofsensors and to control operation of the heat exchanger to selectivelycool the sump by the heat exchanger based on the sensor data to promotefuel economy in use of the transmission system.

In some embodiments, the plurality of sensors may include a first brakesensor configured to provide brake sensor data indicative of a state ofa first braking device of the vehicle and a fault diagnostic sensorconfigured to provide fault diagnostic data indicative of a fault stateof the vehicle, and the instructions stored in the memory device may beexecutable by the processor to cause the processor to receive the brakesensor data from the first brake sensor and the fault diagnostic datafrom the fault diagnostic sensor and to selectively cool the sump by theheat exchanger based on the brake sensor data and the fault diagnosticdata. The brake sensor data from the first brake sensor may beindicative of a state of a retarder of the vehicle, the plurality ofsensors may include a second brake sensor configured to provide brakesensor data indicative of a state of an engine brake of the vehicle, andthe instructions stored in the memory device may be executable by theprocessor to cause the processor to: receive the brake sensor data fromthe first and second brake sensors and the fault diagnostic data fromthe fault diagnostic sensor; determine whether the retarder is activebased on the brake sensor input from the first brake sensor; determinewhether the engine brake is active based on the brake sensor input fromthe second brake sensor; determine whether a fault is present based onthe fault diagnostic data from the fault diagnostic sensor; and cool thesump by the heat exchanger in response to a determination that theretarder is active, that the engine brake is active, or that a fault ispresent.

In some embodiments, the instructions stored in the memory device may beexecutable by the processor to cause the processor to, in response to adetermination that the retarder is inactive, that the engine brake isinactive, and that a fault is not present, determine whether a predictedtemperature of the sump is greater than a first temperature threshold orwhether a current temperature of the sump is greater than a secondtemperature threshold, and to cool the sump by the heat exchanger inresponse to a determination that the predicted temperature of the sumpis greater than the first temperature threshold or a determination thatthe current temperature of the sump is greater than the secondtemperature threshold. The instructions stored in the memory device maybe executable by the processor to cause the processor to, in response todetermination that the predicted temperature of the sump is not greaterthan the first temperature threshold and a determination that thecurrent temperature of the sump is not greater than the secondtemperature threshold, determine whether the predicted temperature ofthe sump is less than the first temperature threshold and whether thecurrent temperature of the sump is less than a third temperaturethreshold, and to disable cooling of the sump by the heat exchanger inresponse to a determination that the predicted temperature of the sumpis less than the first temperature threshold and the current temperatureof the sump is less than the third temperature threshold.

In some embodiments, the instructions stored in the memory device may beexecutable by the processor to cause the processor to selectively coolthe sump based on a predicted temperature of the sump in use of thetransmission system. The instructions stored in the memory device may beexecutable by the processor to cause the processor to predict the sumptemperature based on a predicted rate of change in sump temperature(Δ_(temp)) multiplied by a prediction time interval (t_(horizon)) andsummed with a current sump temperature value (T_(n)). The instructionsstored in the memory device may be executable by the processor to causethe processor to predict the rate of change in sump temperature(Δ_(temp)) based on a previous predicted rate of change of sumptemperature (Δ_(temp_previous)), the current sump temperature samplevalue (T_(n)), a previous sump temperature sample value (T_(n-1)), atime measurement rate (t_(measurement_rate)), and a constant referencevalue (K_(filter)), and the instructions stored in the memory device maybe executable by the processor to cause the processor to predict therate of change in sump temperature (Δ_(temp)) according to the equation

Δ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter).

In some embodiments, the instructions stored in the memory device may beexecutable by the processor to cause the processor to determine theconstant reference value (K_(filter)) based on temperature sensor dataindicative of an ambient air temperature and based on mode sensor dataindicative of an operational mode of a torque converter or a retarder.Additionally, in some embodiments, the instructions stored in the memorydevice may be executable by the processor to cause the processor todetermine the current sump temperature sample value (T_(n)) and theprevious sump temperature sample value (T_(n-1)) over one second timeintervals and to determine the prediction time interval (t_(horizon))over thirty second intervals.

In some embodiments, the instructions stored in the memory device mayexecutable by the processor to cause the processor to: receive brakesensor data from a first brake sensor indicative of a state of aretarder of the vehicle; receive brake sensor data from a second brakesensor indicative of a state of an engine brake of the vehicle; receivebrake sensor data from a third brake sensor indicative of a state of aservice brake of the vehicle; receive fault data from a fault diagnosticsensor indicative of a fault state of the vehicle; receive grade datafrom an inclinometer indicative of a grade of a surface on which thevehicle is positioned; receive accelerator data from an acceleratorsensor indicative of depression of an accelerator pedal of the vehicle;receive temperature data from an air temperature sensor indicative ofthe ambient air temperature; receive input provided by an operator;receive mode sensor data from a torque converter sensor indicative of anoperational mode of a torque converter; and selectively cool the sump bythe heat exchanger based on the brake sensor data from the first,second, and third brake sensors, the fault data, the grade data, theaccelerator data, the temperature data, the input provided by theoperator, and the mode sensor data.

According to another aspect of the present disclosure, a control systemfor a vehicle that includes a transmission configured to receiverotational power supplied by a drive unit and provide the rotationalpower to a load and a heat exchanger fluidly coupled to the transmissionand configured to cool a sump of the transmission to manage transmissionoil temperature may include a first brake sensor, a fault diagnosticsensor, and a controller. The first brake sensor may be configured toprovide brake sensor data indicative of a state of a first brakingdevice of the vehicle. The fault diagnostic sensor may be configured toprovide fault diagnostic data indicative of a fault state of thevehicle. The controller may be communicatively coupled to the firstbrake sensor and the fault diagnostic sensor, and the controller mayinclude a memory device having instructions stored therein that areexecutable by a processor to cause the processor to receive the brakesensor data from the first brake sensor and the fault diagnostic datafrom the fault diagnostic sensor and to selectively cool the sump by theheat exchanger based on the brake sensor data and the fault diagnosticdata to promote fuel economy in use of the transmission system.

In some embodiments, the control system may include a second brakesensor configured to provide brake sensor data indicative of a state ofa second braking device of the vehicle, and the instructions stored inthe memory may be executable by the processor to cause the processor to:receive the brake sensor data from the first and second brake sensorsand the fault diagnostic data from the fault diagnostic sensor;determine whether a retarder of the vehicle is active based on the brakesensor data from the first brake sensor; determine whether an enginebrake of the vehicle is active based on the brake sensor data from thesecond brake sensor; determine whether a fault is present based on thefault diagnostic data from the fault diagnostic sensor; and cool thesump by the heat exchanger in response to a determination that theretarder is active, that the engine brake is active, or that a fault ispresent. The instructions stored in the memory device may be executableby the processor to cause the processor to, in response to adetermination that the retarder is inactive, that the engine brake isinactive, and that a fault is not present, determine whether a predictedtemperature of the sump is greater than a first temperature threshold orwhether a current temperature of the sump is greater than a secondtemperature threshold, and to cool the sump by the heat exchanger inresponse to a determination that the predicted temperature of the sumpis greater than the first temperature threshold or a determination thatthe current temperature of the sump is greater than the secondtemperature threshold.

In some embodiments, the instructions stored in the memory device may beexecutable by the processor to cause the processor to, in response to adetermination that the predicted temperature of the sump is not greaterthan the first temperature threshold and a determination that thecurrent temperature of the sump is not greater than the secondtemperature threshold, determine whether the predicted temperature ofthe sump is less than the first temperature threshold and whether thecurrent temperature of the sump is less than a third temperaturethreshold, and to disable cooling of the sump by the heat exchanger inresponse to a determination that the predicted temperature of the sumpis less than the first temperature threshold and the current temperatureof the sump is less than the third temperature threshold. Additionally,in some embodiments, the instructions stored in the memory device may beexecutable by the processor to cause the processor to: selectively coolthe sump based on a predicted temperature of the sump in use of thetransmission system; predict the sump temperature based on a predictedrate of change in sump temperature (Δ_(temp)) multiplied by a predictiontime interval (t_(horizon)) and summed with a current sump temperaturevalue (T_(n)); and predict the rate of change in sump temperature(Δ_(temp)) based on a previous predicted rate of change of sumptemperature (Δ_(temp_previous)), a current sump temperature sample value(T_(n)), a previous sump temperature sample value (T₁), a timemeasurement rate (t_(measurement_rate)), and a constant reference value(K_(filter)) according to the equation

Δ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter).

According to yet another aspect of the present disclosure, a method ofoperating a vehicle that includes a transmission configured to receiverotational power supplied by a drive unit and provide the rotationalpower to a load and a heat exchanger fluidly coupled to the transmissionand configured to cool a sump of the transmission to manage transmissionoil temperature may include receiving, by a controller of thetransmission system, brake sensor data provided by a first brake sensorof the transmission system that is indicative of a state of a firstbraking device of the vehicle; receiving, by the controller, faultdiagnostic data provided by a fault diagnostic sensor of thetransmission system that is indicative of a fault state of the vehicle;and selectively cooling, by the controller using the heat exchanger, thesump based on the brake sensor data and the fault diagnostic data topromote fuel economy in use of the transmission system.

In some embodiments, the method may include receiving, by thecontroller, brake sensor data provided by a second brake sensor of thetransmission system that is indicative of a state of a second brakingdevice of the vehicle; determining, by the controller, whether aretarder of the vehicle is active based on the brake sensor input datathe first brake sensor; determining, by the controller, whether anengine brake of the vehicle is active based on the brake sensor datafrom the second brake sensor; determining, by the controller, whether afault is present based on the fault diagnostic data from the faultdiagnostic sensor; and cooling, by the controller using the heatexchanger, the sump in response to a determination that the retarder isactive, that the engine brake is active, or that a fault is present. Themethod may include determining, by the controller in response to adetermination that the retarder is inactive, that the engine brake isinactive, or that a fault is not present, whether a predictedtemperature of the sump is greater than a first temperature threshold orwhether a current temperature of the sump is greater than a secondtemperature threshold; and cooling, by the controller using the heatexchanger, the sump in response to a determination that the predictedtemperature of the sump is greater than the first temperature thresholdor a determination that the current temperature of the sump is greaterthan the second temperature threshold. Additionally, in someembodiments, the method may include selectively cooling, by thecontroller using the heat exchanger, the sump based on a predictedtemperature of the sump in use of the transmission system; predicting,by the controller, the sump temperature based on a predicted rate ofchange in sump temperature (Δ_(temp)) multiplied by a prediction timeinterval (t_(horizon)) and summed with a current sump temperature value(T_(n)); and predicting, by the controller, the rate of change in sumptemperature (Δ_(temp)) based on a previous predicted rate of change ofsump temperature (Δ_(temp_previous)), a current sump temperature samplevalue (T_(n)), a previous sump temperature sample value (T_(n-1)), atime measurement rate (t_(measurement_rate)), and a constant referencevalue (K_(filter)) according to the equation

Δ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter).

These and other features of the present disclosure will become moreapparent from the following description of the illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention described herein is illustrated by way of example and notby way of limitation in the accompanying figures. For simplicity andclarity of illustration, elements illustrated in the figures are notnecessarily drawn to scale. For example, the dimensions of some elementsmay be exaggerated relative to other elements for clarity. Further,where considered appropriate, reference labels have been repeated amongthe figures to indicate corresponding or analogous elements.

FIG. 1 is a diagrammatic view of a drive system for a vehicle;

FIG. 2 is a diagrammatic view of a transmission system included in thedrive system of FIG. 1;

FIG. 3 is a diagrammatic view of a control system for the drive systemof FIG. 1;

FIG. 4 is a diagrammatic view of a number of modules that may beincluded in a controller of the control system shown in FIG. 3;

FIG. 5 is a simplified flowchart of a method that may be performed by asump temperature management and cooling system control module inconjunction with performance of a prediction scheme by one of two sumptemperature prediction modules of the controller diagrammaticallydepicted in FIG. 4;

FIG. 6 is a simplified flowchart of another method that may be performedby the sump temperature management and cooling system control module inconjunction with performance of a prediction scheme by one of two sumptemperature prediction modules of the controller diagrammaticallydepicted in FIG. 4;

FIG. 7 is a table depicting various input and output states associatedwith the performance of the method of FIG. 6;

FIG. 8 is a block diagram illustrating performance of a predictionmethod by one of the sump temperature prediction modules of thecontroller diagrammatically depicted in FIG. 4;

FIG. 9 is a block diagram depicting multiple communicative couplingsthat may be established between the controller and a cooling systemincluded in the transmission system during the performance of the methodillustrated in FIG. 8;

FIG. 10 is a simplified flowchart of another method that may beperformed by the sump temperature management and cooling system controlmodule of the controller diagrammatically depicted in FIG. 4; and

FIG. 11 is a block diagram depicting communication between thecontroller and the cooling system via a controller area network duringthe performance of the method illustrated in FIG. 8.

DETAILED DESCRIPTION

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific embodiments thereof havebeen shown by way of example in the drawings and will be describedherein in detail. It should be understood, however, that there is nointent to limit the concepts of the present disclosure to the particularforms disclosed, but on the contrary, the intention is to cover allmodifications, equivalents, and alternatives consistent with the presentdisclosure and the appended claims.

References in the specification to “one embodiment,” “an embodiment,”“an illustrative embodiment,” etc., indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but every embodiment may or may not necessarily includethat particular feature, structure, or characteristic. Moreover, suchphrases are not necessarily referring to the same embodiment. Further,when a particular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the art to effect such feature, structure,or characteristic in connection with other embodiments whether or notexplicitly described. Additionally, it should be appreciated that itemsincluded in a list in the form of “at least one A, B, and C” can mean(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).Similarly, items listed in the form of “at least one of A, B, or C” canmean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).

In the drawings, some structural or method features, such as thoserepresenting devices, modules, instructions blocks and data elements,may be shown in specific arrangements and/or orderings for ease ofdescription. However, it should be appreciated that such specificarrangements and/or orderings may not be required. Rather, in someembodiments, such features may be arranged in a different manner and/ororder than shown in the illustrative figures. Additionally, theinclusion of a structural or method feature in a particular figure isnot meant to imply that such feature is required in all embodiments and,in some embodiments, may not be included or may be combined with otherfeatures.

In some embodiments, schematic elements used to represent blocks of amethod may be manually performed by a user. In other embodiments,implementation of those schematic elements may be automated using anysuitable form of machine-readable instruction, such as software orfirmware applications, programs, functions, modules, routines,processes, procedures, plug-ins, applets, widgets, code fragments and/orothers, for example, and each such instruction may be implemented usingany suitable programming language, library, application programminginterface (API), and/or other software development tools. For instance,in some embodiments, the schematic elements may be implemented usingJava, C++, and/or other programming languages. Similarly, schematicelements used to represent data or information may be implemented usingany suitable electronic arrangement or structure, such as a register,data store, table, record, array, index, hash, map, tree, list, graph,file (of any file type), folder, directory, database, and/or others, forexample.

Further, in the drawings, where connecting elements, such as solid ordashed lines or arrows, are used to illustrate a connection,relationship, or association between or among two or more otherschematic elements, the absence of any such connection elements is notmeant to imply that no connection, relationship, or association canexist. In other words, some connections, relationships, or associationsbetween elements may not be shown in the drawings so as not to obscurethe disclosure. In addition, for ease of illustration, a singleconnecting element may be used to represent multiple connections,relationships, or associations between elements. For example, where aconnecting element represents a communication of signals, data orinstructions, it should be understood by those skilled in the art thatsuch element may represent one or multiple signal paths (e.g., a bus),as may be needed, to effect the communication.

Referring now to FIG. 1, an illustrative drive system 100 for a vehicleincludes a transmission system 200 (see FIG. 2) that has a transmission120 and a heat exchanger 204. The transmission 120 is configured toreceive rotational power supplied by a drive unit 102 and provide therotational power to a load (e.g., an axle 132 and wheels 134A, 134Bmounted thereto) in use of the transmission system 200. The heatexchanger 204 is fluidly coupled to the transmission 120 and configuredto cool a sump 222 of the transmission 120 to manage transmission oiltemperature in use of the transmission system 200.

In the illustrative embodiment, the transmission 120 includes a controlsystem 300 (see FIG. 3) that is configured to control operation ofvarious components of the transmission 120 (e.g., one or more clutches,an electro-hydraulic system 138) and operation of a cooling system 202that includes the heat exchanger 204. The control system 300 includes atleast one sensor or sensing device (e.g., one or more of sensingdevice(s) 310, 312, 314 and fault diagnostic device(s) 316) configuredto provide sensor data indicative of a state of a braking device of thevehicle or a fault state of the vehicle. Additionally, the controlsystem 300 includes a controller 302 that is communicatively coupled tothe at least one sensor or sensing device. As described in greaterdetail below with reference to FIGS. 5 and 6, the controller 302includes a processor 304 and a memory device 306 coupled to theprocessor 304, and the memory device 306 has instructions stored thereinthat are executable by the processor 304 to cause the processor 304 toreceive the sensor data from the at least one sensor and to controloperation of the heat exchanger 204 to selectively cool the sump 222 bythe heat exchanger 204 based on the sensor data to promote fuel economyin use of the transmission system 200.

It should be appreciated that control of the transmission 120 and thecooling system 202 by the illustrative control system 300, and otherconcepts of the present disclosure attendant to that control,selectively enables and disables cooling of the sump 222 by the heatexchanger 204 in certain vehicle operational states to promote fueleconomy in a unique manner. In some embodiments, the control system 300may disable cooling by the heat exchanger 204 during relativelyhigh-load conditions, such as during acceleration of the vehicle, forexample. Additionally, in some embodiments, the control system 300 mayenable cooling by the heat exchanger 204 during relatively low-loadconditions, such as during deceleration of the vehicle, for example. Indoing so, the control system 300 may cool the sump 222 by the heatexchanger 204 so that the sump temperature reaches, or otherwiseapproaches, a target sump temperature value that corresponds to, or isotherwise associated with, a desired fuel economy of the vehicle.

Furthermore, it should be appreciated that control of the cooling system202 by the illustrative control system 300, and other concepts of thepresent disclosure attendant to that control, facilitates diagnosis offaults (e.g., faults related to overheating of the sump 222) in a uniquemanner. In some embodiments, rather than logging a general fault codeassociated with the transmission 120 (e.g., overheating of the sump222), the control system 300 may log or generate a fault code specificto the operation of one or more fans 206 of the heat exchanger 204,which may reduce troubleshooting time and cost. In addition, as will beapparent from the discussion that follows, at least in some embodiments,control of the cooling system 202 may be performed by the control system300 without a sensing device associated with the heat exchanger 204 thatmonitors transmission oil temperature, thereby reducing cost.

Further still, it should be appreciated that the illustrative drivesystem 100 is adapted for use in one or more vehicles employed in avariety of applications. In some embodiments, the drive system 100 maybe adapted for use with, or otherwise incorporated into, fire andemergency vehicles, refuse vehicles, coach vehicles, RVs and motorhomes,municipal and/or service vehicles, agricultural vehicles, miningvehicles, specialty vehicles, energy vehicles, defense vehicles, portservice vehicles, construction vehicles, and transit and/or busvehicles, just to name a few. Additionally, in some embodiments, thedrive system 100 may be adapted for use with, or otherwise incorporatedinto, tractors, front end loaders, scraper systems, cutters andshredders, hay and forage equipment, planting equipment, seedingequipment, sprayers and applicators, tillage equipment, utilityvehicles, mowers, dump trucks, backhoes, track loaders, crawler loaders,dozers, excavators, motor graders, skid steers, tractor loaders, wheelloaders, rakes, aerators, skidders, bunchers, forwarders, harvesters,swing machines, knuckleboom loaders, diesel engines, axles, planetarygear drives, pump drives, transmissions, generators, and marine engines,among other suitable equipment.

The illustrative transmission 120 has an input shaft 122, an outputshaft 124, and one or more clutches (not shown). The input shaft 122 isconfigured to receive rotational power supplied by the drive unit 102.The output shaft 124 is coupled to the input shaft 122 and configured toprovide rotational power supplied to the input shaft 122 to the axle 132and the wheels 134A, 134B mounted thereto. The one or more clutches maybe included in, or otherwise adapted for use with, the electro-hydraulicsystem 138 and coupled between the input shaft 122 and the output shaft124 to selectively transmit rotational power between the shafts 122, 124in one or more operating modes of the transmission 120. Each of the oneor more clutches may be selectively engageable in response to one ormore fluid pressures applied thereto.

In the illustrative embodiment, the drive unit 102 is embodied as, orotherwise includes, any device capable of producing rotational power todrive other components (e.g., a torque converter 108 and thetransmission 120) of the drive system 100 in use thereof. In someembodiments, the drive unit 102 may be embodied as, or otherwiseinclude, an internal combustion engine, diesel engine, electric motor,or other power-generating device. In any case, the drive unit 102 isconfigured to rotatably drive an output shaft 104 that is coupled to aninput or pump shaft 106 of a torque converter 108.

The input or pump shaft 106 of the illustrative torque converter 108 iscoupled to an impeller or pump 110 that is rotatably driven by theoutput shaft 104 of the drive unit 102. The torque converter 108 furtherincludes a turbine 112 that is coupled to a turbine shaft 114. In theillustrative embodiment, the turbine shaft 114 is coupled to, orintegral with, the input shaft 122 of the transmission 120.

The illustrative torque converter 108 also includes a lockup clutch 136connected between the pump 110 and the turbine 112 of the torqueconverter 108. The torque converter 108 is operable in a so-called“torque converter” mode during certain operating conditions, such asduring vehicle launch, low speed conditions, and certain gear shiftingconditions, for example. In the torque converter mode, the lockup clutch136 is disengaged and the pump 110 rotates at the rotational speed ofthe drive unit output shaft 104 while the turbine 112 is rotatablyactuated by the pump 110 through a fluid (not shown) interposed betweenthe pump 110 and the turbine 112. In this operational mode, torquemultiplication occurs through the fluid coupling such that the turbineshaft 114 is exposed to more torque than is being supplied by the driveunit 102. The torque converter 108 is alternatively operable in aso-called “lockup” mode during other operating conditions, such as whentorque multiplication is not needed, for example. In the lockup mode,the lockup clutch 136 is engaged and the pump 110 is thereby secureddirectly to the turbine 112 so that the drive unit output shaft 104 isdirectly coupled to the input shaft 124 of the transmission 118 throughthe torque converter 108.

In the illustrative embodiment, the transmission 120 includes aninternal pump 118 configured to pressurize, and/or distribute fluidtoward, one or more fluid (e.g., hydraulic fluid) circuits thereof. Insome embodiments, the pump 118 may be configured to pressurize, and/ordistribute fluid toward, a main circuit, a lube circuit, anelectro-hydraulic control circuit, and/or any other circuit incorporatedinto the electro-hydraulic system 138, for example. It should beappreciated that in some embodiments, the pump 118 may be driven by ashaft 116 that is coupled to the output shaft 104 of the drive unit 102.In this arrangement, the drive unit 102 can deliver torque to the shaft116 for driving the pump 118 and building pressure within the differentcircuits of the transmission 120.

The illustrative transmission 120 includes a gearing system 126 coupledbetween the input shaft 122 and the output shaft 124. It should beappreciated that the gearing system 126 may include one or more geararrangements (e.g., planetary gear arrangements, epicyclic drivearrangements, etc.) that provide, or are otherwise associated with, oneor more gear ratios. When used in combination with the electro-hydraulicsystem 138 under control by the control system 300, the gearing system126 may provide, or otherwise be associated with, one or more operatingranges selected by an operator.

The output shaft 124 of the transmission 120 is illustratively coupledto, or otherwise integral with, a propeller shaft 128. The propellershaft 128 is coupled to a universal joint 130 which is coupled to, androtatably drives, the axle 132 and the wheels 134A, 134B. In thisarrangement, the output shaft 124 drives the wheels 134A, 134B throughthe propeller shaft 128, the universal joint 130, and the axle 132 inuse of the drive system 100.

The illustrative transmission 120 includes the electro-hydraulic system138 that is fluidly coupled to the gearing system 126 via a number(i.e., J) of fluid paths 1401-140J, where J may be any positive integer.The electro-hydraulic system 138 is configured to receive controlsignals provided by various electro-hydraulic control devices (notshown), such as one or more sensors and one or more flow and/or pressurecontrol devices, for example. In response to those control signals, andunder control by the control system 300, the electro-hydraulic system138 selectively causes fluid to flow through one or more of the fluidpaths 1401-140J to control operation (e.g., engagement anddisengagement) of one or more friction devices (e.g., the one or moreclutches) included in, or otherwise adapted for use with, the gearingsystem 126.

Of course, it should be appreciated that the one or more frictiondevices may include, but are not limited to, one or more brake devices,one or more torque transmitting devices (i.e., clutches), and the like.Generally, the operation (e.g., engagement and disengagement) of the oneor more friction devices is controlled by selectively controlling thefriction applied by, or otherwise associated with, each of the one ormore friction devices, such as by controlling fluid pressure applied toeach of the friction devices, for example. In the illustrativeembodiment, which is not intended to be limiting in any way, theelectro-hydraulic system 138 may be coupled to, or otherwise adapted foruse with, one or more brakes. Similar to the clutches, each of the oneor more brakes may be controllably engaged and disengaged via fluidpressure supplied by the electro-hydraulic system 138. In any case,changing or shifting between the various gears of the transmission 120is accomplished by selectively controlling the friction devices viacontrol of fluid pressure within the number of fluid paths 1401-140J.

In the illustrative system 100 shown in FIG. 1, the torque converter 108and the transmission 120 include a number of sensors configured toproduce sensor signals that are indicative of one or more operatingstates of the torque converter 108 and the transmission 120,respectively. For example, the torque converter 108 illustrativelyincludes a speed sensor 146 that is configured to produce a speed signalcorresponding to the rotational speed of the pump shaft 106, whichrotates at the same speed as the output shaft 104 of the drive unit 102in use of the drive system 100. The speed sensor 146 is electricallyconnected to a pump speed input (i.e., PS) of the controller 302 via asignal path 152, and the controller 302 is operable to process the speedsignal produced by the speed sensor 146 to determine the rotationalspeed of the pump shaft 106/drive unit output shaft 104.

In the illustrative system 100, the transmission 120 includes a speedsensor 148 that is configured to produce a speed signal corresponding tothe rotational speed of the transmission input shaft 122, which rotatesat the same speed as the turbine shaft 114 of the torque converter 108in use of the system 100. The input shaft 122 of the transmission 120may be directly coupled to, or otherwise integral with, the turbineshaft 114. Of course, it should be appreciated that the speed sensor 148may alternatively be configured to produce a speed signal correspondingto the rotational speed of the turbine shaft 114. Regardless, the speedsensor 148 is electrically connected to a transmission input shaft speedinput (i.e., TIS) of the controller 302 via a signal path 154, and thecontroller 302 is operable to process the speed signal produced by thespeed sensor 148 to determine the rotational speed of the turbine shaft114/transmission input shaft 124.

Further, in the illustrative system 100, the transmission 120 includes aspeed sensor 150 that is configured to produce a speed signalcorresponding to the rotational speed and direction of the output shaft124 of the transmission 120. The speed sensor 150 is electricallyconnected to a transmission output shaft speed input (i.e., TOS) of thecontroller 302 via a signal path 156. The controller 302 is configuredto process the speed signal produced by the speed sensor 150 todetermine the rotational speed of the transmission output shaft 124.

In some embodiments, the electro-hydraulic system 138 includes one ormore actuators configured to control various operations within thetransmission 120. For example, the electro-hydraulic system 138 mayinclude a number of actuators that are electrically connected to anumber (i.e., J) of control outputs CP1-CPJ of the controller 302 via acorresponding number of signal paths 721-72J, where J may be anypositive integer as described above. Each of the actuators may receive acorresponding one of the control signals CP1-CPJ produced by thecontroller 302 via one of the corresponding signal paths 721-72J. Inresponse thereto, each of the actuators may control the friction appliedby each of the friction devices by controlling the pressure of fluidwithin one or more corresponding fluid passageway 1401-140J, therebycontrolling the operation of one or more corresponding friction devicesbased on information provided by the various speed sensors 146, 148,and/or 150 in use of the system 100.

In the illustrative embodiment, the system 100 includes a drive unitcontroller 160 having an input/output port (I/O) that is electricallycoupled to the drive unit 102 via a number (i.e., K) of signal paths162, wherein K may be any positive integer. The drive unit controller160 is operable to control and manage the overall operation of the driveunit 102. The drive unit controller 160 includes a communication port(i.e., COM) which is electrically connected to a similar communicationport (i.e., COM) of the controller 302 via a number (i.e., L) of signalpaths 164, wherein L may be any positive integer. It should beappreciated that the one or more signal paths 164 may be referred tocollectively as a data link. Generally, the drive unit controller 160and the transmission controller 302 are operable to share informationvia the one or more signal paths 164. In one embodiment, for example,the drive unit controller 160 and the transmission controller 302 areoperable to share information via the one or more signal paths 164 inthe form of one or more messages in accordance with a Society ofAutomotive Engineers (SAE) J-1939 communications protocol. Of course, itshould be appreciated that this disclosure contemplates otherembodiments in which the drive unit controller 160 and the transmissioncontroller 302 are operable to share information via the one or moresignal paths 164 in accordance with one or more other communicationprotocols (e.g., from a conventional databus such as J1587 data bus,J1939 data bus, IESCAN data bus, GMLAN, Mercedes PT-CAN).

Referring now to FIG. 2, the illustrative transmission 120 includes ahydraulic system 220 that has the sump 222, a filter 224, a pump 226,and a control circuit 228, among other things. The sump 222 isconfigured to store transmission oil for distribution to othercomponents of the transmission 120. The filter 224 is configured toremove impurities, debris, and/or foreign matter from the transmissionoil provided by the sump 222. The pump 226 is configured to drivedistribution of filtered transmission oil provided by the sump 222 toother components of the transmission. The control circuit 228 isconfigured to control distribution of the oil provided by the sump 222,and to that end, the control circuit 228 may include, or otherwise beembodied as, one or more solenoid valves, trim valves, pressure controlvalves, accumulators, regulators, pressure orifice devices, restrictors,and/or the like.

The illustrative cooling system 202 includes the heat exchanger 204which has, or is otherwise embodied as, multiple fans 206. In theillustrative embodiment, the fans 206 include a primary fan 208 and oneor more supplemental fans 210. As described below in greater detail withreference to FIG. 10, at least in some embodiments, and based oninstructions stored in the memory 306, the processor 304 is configuredto selectively enable and disable cooling of the sump 222 by the primaryfan 208 and the one or more supplemental fans 210 in use of thetransmission system 200.

In the illustrative embodiment, the heat exchanger 204 is embodied as,or otherwise includes, an oil-to-air (OTA) heat exchanger. The heatexchanger 204 may be embodied as, or otherwise include, any device orcollection of devices capable of transferring heat from the sump 222 toair drawn into the heat exchanger 204 to cool the sump 222 in use of thetransmission system 200, as described below. For example, the heatexchanger 204 may incorporate, or otherwise be embodied as, a shell andtube heat exchanger, a plate heat exchanger, a shell and plate heatexchanger, an adiabatic wheel heat exchanger, a plate fin heatexchanger, a helical-coil heat exchanger, a spiral heat exchanger, aheat exchanger incorporating HVAC coils, or the like.

When the cooling system 202 cools the sump 222 in use of thetransmission system 200, uncooled oil 230 is supplied to the heatexchanger 204 via a supply line 232 and air 234 is drawn into the heatexchanger 204 as a consequence of operation of the fans 206. Heat fromthe uncooled oil 230 is transferred to the air 234 to provide cooled oil236 which is returned to the sump 222 via a return line 238. Heated air240 is expelled from the heat exchanger 204.

Referring now to FIG. 3, in the illustrative embodiment, the controlsystem includes the sensors 146, 148, 150, the controller 302, theservice brake sensing device 310, the retarder sensing device 312, theengine brake sensing device 314, the one or more fault diagnosticdevice(s) 316, a dashboard 318, an ambient air temperature sensingdevice 326, a torque converter mode sensing device 328, an acceleratorsensing device 330, an inclinometer 332, a fan activation relay 334, asump temperature sensing device 336, and a thermostat 338. Each of thedevices 146, 148, 150, 310, 312, 314, 316, 318, 326, 328, 330, 332, 334,336, 338 is communicatively coupled to the controller 302, such as by adirect (e.g., hardwired) connection or a controller area network (CAN)interface, for example.

The processor 304 of the illustrative controller 302 may be embodied as,or otherwise include, any type of processor, controller, or othercompute circuit capable of performing various tasks such as computefunctions and/or controlling the functions of the transmission 120, thecooling system 202, and, at least in some embodiments, the torqueconverter 108. For example, the processor 304 may be embodied as asingle or multi-core processor(s), a microcontroller, or other processoror processing/controlling circuit. In some embodiments, the processor304 may be embodied as, include, or otherwise be coupled to an FPGA, anapplication specific integrated circuit (ASIC), reconfigurable hardwareor hardware circuitry, or other specialized hardware to facilitateperformance of the functions described herein. Additionally, in someembodiments, the processor 304 may be embodied as, or otherwise include,a high-power processor, an accelerator co-processor, or a storagecontroller. In some embodiments still, the processor 304 may includemore than one processor, controller, or compute circuit.

The memory device 306 of the illustrative controller 302 may be embodiedas any type of volatile (e.g., dynamic random access memory (DRAM),etc.) or non-volatile memory capable of storing data therein. Volatilememory may be embodied as a storage medium that requires power tomaintain the state of data stored by the medium. Non-limiting examplesof volatile memory may include various types of random access memory(RAM), such as dynamic random access memory (DRAM) or static randomaccess memory (SRAM). One particular type of DRAM that may be used in amemory module is synchronous dynamic random access memory (SDRAM). Inparticular embodiments, DRAM of a memory component may comply with astandard promulgated by JEDEC, such as JESD79F for DDR SDRAM, JESD79-2Ffor DDR2 SDRAM, JESD79-3F for DDR3 SDRAM, JESD79-4A for DDR4 SDRAM,JESD209 for Low Power DDR (LPDDR), JESD209-2 for LPDDR2, JESD209-3 forLPDDR3, and JESD209-4 for LPDDR4 (these standards are availableatwww.jedec.org). Such standards (and similar standards) may be referredto as DDR-based standards and communication interfaces of the storagedevices that implement such standards may be referred to as DDR-basedinterfaces.

In some embodiments, the memory device 306 may be embodied as a blockaddressable memory, such as those based on NAND or NOR technologies. Thememory device 306 may also include future generation nonvolatiledevices, such as a three dimensional crosspoint memory device (e.g.,Intel 3D XPoint™ memory), or other byte addressable write-in-placenonvolatile memory devices. In some embodiments, the memory device 306may be embodied as, or may otherwise include, chalcogenide glass,multi-threshold level NAND flash memory, NOR flash memory, single ormulti-level Phase Change Memory (PCM), a resistive memory, nanowirememory, ferroelectric transistor random access memory (FeTRAM),anti-ferroelectric memory, magnetoresistive random access memory (MRAM)memory that incorporates memristor technology, resistive memoryincluding the metal oxide base, the oxygen vacancy base and theconductive bridge Random Access Memory (CB-RAM), or spin transfer torque(STT)-MRAM, a spintronic magnetic junction memory based device, amagnetic tunneling junction (MTJ) based device, a DW (Domain Wall) andSOT (Spin Orbit Transfer) based device, a thyristor based memory device,or a combination of any of the above, or other memory. The memory devicemay refer to the die itself and/or to a packaged memory product. In someembodiments, 3D crosspoint memory (e.g., Intel 3D XPoint™ memory) maycomprise a transistor-less stackable cross point architecture in whichmemory cells sit at the intersection of word lines and bit lines and areindividually addressable and in which bit storage is based on a changein bulk resistance.

The illustrative service brake sensing device 310 is embodied as, orotherwise includes, any device or collection of devices capable ofdetecting an operational characteristic of a service brake of thevehicle, such as depression (or lack thereof) of the service brake by anoperator, engagement or activation, and/or disengagement ordeactivation, for example. In some embodiments, the sensing device 310may be embodied as, or otherwise include, a pressure sensor, a positionsensor, or the like, for example. Of course, in other embodiments, itshould be appreciated that the sensing device 310 may be embodied as, orotherwise include, another suitable device.

The illustrative retarder sensing device 312 is embodied as, orotherwise includes, any device or collection of devices capable ofdetecting an operational characteristic of a retarder of the vehicle,such as depression (or lack thereof) of the retarder by an operator,engagement or activation, and/or disengagement or deactivation, forexample. In some embodiments, the sensing device 312 may be embodied as,or otherwise include, a pressure sensor, a position sensor, or the like,for example. Of course, in other embodiments, it should be appreciatedthat the sensing device 312 may be embodied as, or otherwise include,another suitable device.

It should be appreciated that in some configurations, the retarder maybe installed as a component separate from the transmission 120, similarto the configuration of some Allison LCT series transmissions, forexample. In such configurations, the retarder may be remotely installedand operated without being cooled by transmission oil (e.g., oil storedin the sump 222). Additionally, it should be appreciated that in someconfigurations, the retarded may optionally be included in thetransmission 120, similar to the configuration of some Allison WT seriestransmissions, for example.

In the illustrative embodiment, the retarder is a braking device orsystem that is configured to convert the kinetic energy of the vehicleinto thermal energy, which may heat the transmission oil stored in thesump 222. Of course, it should be appreciated that the retarder may beactivated and/or de-activated by multiple mechanisms independently of,or in combination with, one another. In one example, the retarder may beactivated in combination with the service brake of the vehicle. Inanother example, the retarder may be activated by a lever on thedashboard 318 independently of the service brake. In yet anotherexample, the retarder may be activated by a cruise control device tomaintain the cruise set speed in one or more operational conditions(e.g., vehicle travel downhill) independently of the service brake. Inyet another example still, the retarder may be activated by an adaptivecruise control device to maintain the set distance between the front ofthe vehicle and a proximate object, such as another vehicle. Finally,the retarder may be activated to facilitate setup and/or operation ofone or more speed limiting devices.

The illustrative engine brake sensing device 314 is embodied as, orotherwise includes, any device or collection of devices capable ofdetecting an operational characteristic of an engine brake of thevehicle, such as depression (or lack thereof) of the engine brake by anoperator, engagement or activation, and/or disengagement ordeactivation, for example. In some embodiments, the sensing device 314may be embodied as, or otherwise include, a pressure sensor, a positionsensor, or the like, for example. Of course, in other embodiments, itshould be appreciated that the sensing device 314 may be embodied as, orotherwise include, another suitable device.

The illustrative one or more fault diagnostic device(s) 316 are eachembodied as, or otherwise includes, any device or collection of devicescapable of detecting a fault state of the vehicle, particularly a faultstate related to operation of the transmission system 200, such as anoverheating fault associated with the transmission 120 and/or thecooling system 202, for example. In some embodiments, the diagnosticdevice(s) 316 may each be embodied as, or otherwise include, atemperature sensor, a pressure sensor, a position sensor, or the like,for example. Of course, in other embodiments, it should be appreciatedthat each of the diagnostic device(s) 316 may be embodied as, orotherwise include, another suitable device.

The dashboard 318 of the illustrative control system 300 includes adisplay 320 and a user interface 322. The display 320 is configured tooutput or display various indications, messages, and/or prompts to anoperator, which may be generated by the control system 300. The userinterface 322 is configured to provide various inputs to the controlsystem 300 based on various actions, which may include actions performedby an operator. To that end, the user interface 322 includes one or moreinput devices 324.

The illustrative ambient air temperature sensing device 326 is embodiedas, or otherwise includes, any device or collection of devices capableof detecting ambient air temperature. In some embodiments, the sensingdevice 326 may be embodied as, or otherwise include, a temperaturesensor, a humidity sensor, or the like, for example. Of course, in otherembodiments, it should be appreciated that the sensing device 326 may beembodied as, or otherwise include, another suitable device.

The illustrative torque converter mode sensing device 328 is embodiedas, or otherwise includes, any device or collection of devices capableof detecting an operational characteristic of the torque converter 108,such as operation of the torque converter 108 in a lockup mode (in whichthe lockup clutch 136 is engaged) and in a converter mode (in which thelockup clutch 136 is disengaged), for example. In some embodiments, thesensing device 328 may be embodied as, or otherwise include, a pressuresensor, a temperature sensor, a position sensor, or the like, forexample. Of course, in other embodiments, it should be appreciated thatthe sensing device 328 may be embodied as, or otherwise include, anothersuitable device.

The illustrative accelerator sensing device 330 is embodied as, orotherwise includes, any device or collection of devices capable ofdetecting an operational characteristic of an accelerator or throttle ofthe vehicle, such as depression (or lack thereof) of the accelerator byan operator, engagement or activation, and/or disengagement ordeactivation, for example. In some embodiments, the sensing device 330may be embodied as, or otherwise include, a pressure sensor, a positionsensor, or the like, for example. Of course, in other embodiments, itshould be appreciated that the sensing device 330 may be embodied as, orotherwise include, another suitable device.

The inclinometer 332 is embodied as, or otherwise includes, any deviceor collection of devices capable of detecting a grade of a surface onwhich the vehicle carrying the transmission system 200 is positioned. Insome embodiments, the inclinometer 332 may be embodied as, or otherwiseinclude, a tilt sensor, a level gauge, a gradient meter, or the like,for example. Of course, in other embodiments, it should be appreciatedthat the inclinometer 332 may be embodied as, or otherwise include,another suitable device.

The fan activation relay 334, which is included in the cooling system202, is embodied as, or otherwise includes, any device or collection ofdevices capable of selectively activating (e.g., selectively providingelectrical energy to) one or more electrically powered components of theheat exchanger 204 (e.g., the fans 206) to drive operation thereof. Insome embodiments, the fan activation relay 334 may be embodied as, orotherwise include, a switch, a contactor, a solid-state relay, aprotective relay, or the like, for example. Of course, in otherembodiments, it should be appreciated that the relay 334 may be embodiedas, or otherwise include, another suitable device.

The illustrative sump temperature sensing device 336 is embodied as, orotherwise includes, any device or collection of devices capable ofsensing the temperature of the sump 222. In some embodiments, thesensing device 336 may be embodied as, or otherwise include, atemperature sensor, a humidity sensor, or the like, for example. Ofcourse, in other embodiments, it should be appreciated that the sensingdevice 336 may be embodied as, or otherwise include, another suitabledevice.

The illustrative thermostat 338 is embodied as, or otherwise includes,any device or collection of devices capable of sensing and/or adjustingthe temperature of the sump 222 toward a target value to reduce thedifference between a sensed or measured temperature and a desiredtemperature. In some embodiments, the thermostat 338 may be included in,integrated with, or otherwise form a portion of, the controller 302. Insuch embodiments, the thermostat 338 may be configured to at leastpartially perform the functions, methods, and/or activities describedbelow to manage the temperature of the sump 222 in use of thetransmission system 200. Additionally, in some embodiments, thethermostat 338 may be included in place of, or as an alternative to, thesump temperature sensing device 336.

In some embodiments, the devices 146, 148, 150, 310, 312, 314, 316, 324,326, 328, 330, 332, 336 may be embodied as, or otherwise include, inputdevices configured to provide input data and/or signals to thecontroller 302. Additionally, in some embodiments, the fan activationrelay 334 and the thermostat 338 may be embodied as, or otherwiseinclude, output devices configured to receive output data and/or signalsprovided by the controller 302 in response to the input data and/orsignals.

Referring now to FIG. 4, in the illustrative embodiment, the controller302 establishes an environment 400 during operation. The illustrativeenvironment 400 includes a sump temperature management and coolingsystem control module 402, a sump temperature prediction module 404, anda sump temperature prediction module 406. Additionally, in someembodiments, the environment 400 may include a braking detection module408 and a transmission diagnostic control module 410.

Each of the modules, logic, and other components of the environment 400may be embodied as hardware, firmware, software, or a combinationthereof. As such, in some embodiments, one or more modules of theenvironment 400 may be embodied as circuitry or a collection ofelectrical devices. In such embodiments, one or more of the sumptemperature management and cooling system control module 402, the sumptemperature prediction module 404, the sump temperature predictionmodule 406, the braking detection module 408, and the transmissiondiagnostic control module 410 may form a portion of the processor(s) 304and/or other components of the controller 302. Additionally, in someembodiments, one or more of the illustrative modules may form a portionof another module and/or one or more of the illustrative modules may beindependent of one another. Further, in some embodiments, one or more ofthe modules of the environment 400 may be embodied as virtualizedhardware components or emulated architecture, which may be establishedand maintained by the processor(s) 304 or other components of thecontroller 302.

The sump temperature management and cooling system control module 402,which may be embodied as hardware, firmware, software, virtualizedhardware, emulated architecture, and/or a combination thereof asdiscussed above, is configured to receive input data from one or moreinput devices and manage the temperature of the sump 222 in use of thetransmission system 200 based at least partially on the input data and apredicted temperature of the sump 222. To do so, in the illustrativeembodiment, the sump temperature management and cooling system controlmodule 402 may perform the methods described below with reference toFIGS. 5 and 6.

The sump temperature prediction module 404, which may be embodied ashardware, firmware, software, virtualized hardware, emulatedarchitecture, and/or a combination thereof as discussed above, isconfigured to predict the temperature of the sump 222 in use of thetransmission system 200. To do so, in the illustrative embodiment, thesump temperature prediction module 404 may perform the prediction schemedescribed below in greater detail with reference to FIG. 6.

The sump temperature prediction module 406, which may be embodied ashardware, firmware, software, virtualized hardware, emulatedarchitecture, and/or a combination thereof as discussed above, isconfigured to predict the temperature of the sump 222 in use of thetransmission system 200. To do so, in the illustrative embodiment, thesump temperature prediction module 406 may perform the prediction schemedescribed below in greater detail with reference to FIG. 6.

The braking detection module 408, which may be embodied as hardware,firmware, software, virtualized hardware, emulated architecture, and/ora combination thereof as discussed above, may be configured to receiveand/or process input indicative of a state of one or more brakingdevices of the vehicle, such as input provided by the service brakesensing device 310, the retarder sensing device 312, and the enginebrake sensing device 314, for example. Based at least partially on theinput received and/or processed by the braking detection module 408, thecontroller 302 may selectively enable or disable cooling of the sump 222by the heat exchanger 204 as described below in greater detail withreference to FIG. 8.

The transmission diagnostic control module 410, which may be embodied ashardware, firmware, software, virtualized hardware, emulatedarchitecture, and/or a combination thereof as discussed above, may beconfigured to receive and/or process input indicative of a fault stateof the vehicle, such as input provided by the one or more faultdiagnostic device(s) 316, for example. Based at least partially on theinput received and/or processed by the transmission diagnostic controlmodule 410, the controller 302 may selectively enable or disable coolingof the sump 222 by the heat exchanger 204 as described below in greaterdetail with reference to FIG. 8.

Referring now to FIG. 5, an illustrative method 500 of operating thetransmission system 200 may be embodied as, or otherwise include, a setof instructions that are executable by the control system 300 (i.e., thesump temperature management and cooling system control module 402 inconjunction with at least one of the sump temperature prediction modules404, 406). The method 500 corresponds to, or is otherwise associatedwith, performance of the blocks described below in the illustrativesequence of FIG. 5. It should be appreciated, however, that the method500 may be performed in one or more sequences different from theillustrative sequence.

The illustrative method 500 begins with block 502. In block 502, thecontroller 302 receives input data from the devices described above withreference to FIG. 3. To perform block 502, the controller 302 performsblocks 504, 506, 508, 510, 512, 514, 516, 518, 520, 522 described below.

In block 504 of the illustrative method 500, the controller 302 receivesinput data indicative of a measured temperature of the sump 222 in useof the transmission system 200. That is, in block 504, the controller302 receives temperature input data from the sump temperature sensingdevice 336.

In block 506 of the illustrative method 500, the controller 302 receivesinput data indicative of a state of the retarder of the vehicle in useof the transmission system 200. That is, in block 506, the controller302 receives retarder input data from the retarder sensing device 312.

In block 508 of the illustrative method 500, the controller 302 receivesinput data indicative of a state of the engine brake of the vehicle inuse of the transmission system 200. That is, in block 508, thecontroller 302 receives engine brake input data from the engine brakesensing device 314.

In block 510 of the illustrative method 500, the controller 302 receivesinput data indicative of a fault state of the vehicle in use of thetransmission system 200. That is, in block 510, the controller 302receives fault diagnostic input data from the one or more faultdiagnostic device(s) 316.

In block 512 of the illustrative method 500, the controller 302 receivesinput data indicative of a grade of the surface on which the vehicle ispositioned in use of the transmission system 200. That is, in block 512,the controller 302 receives surface grade input data from theinclinometer 332.

In block 514 of the illustrative method 500, the controller 302 receivesinput data indicative of a state of the accelerator in use of thetransmission system 200. That is, in block 514, the controller 302receives accelerator input data from the accelerator sensing device 330.

In block 516 of the illustrative method 500, the controller 302 receivesinput data indicative of the ambient air temperature in use of thetransmission system 200. That is, in block 516, the controller 302receives ambient air temperature input data from the ambient airtemperature sensing device 326.

In block 518 of the illustrative method 500, the controller 302 receivesinput data indicative of a state of the service brake of the vehicle inuse of the transmission system 200. That is, in block 518, thecontroller 302 receives service brake input data from the service brakesensing device 310.

In block 520 of the illustrative method 500, the controller 302 receivesinput data provided by the operator in use of the transmission system200. That is, in block 520, the controller 302 receives operator inputdata from the input device(s) 324.

In block 522 of the illustrative method 500, the controller 302 receivesinput data indicative of a current operational mode of the torqueconverter 108 in use of the transmission system 200. That is, in block522, the controller 302 receives torque converter mode input data fromthe torque converter mode sensing device 528.

From block 502, the illustrative method 500 subsequently proceeds toblock 524. In block 524, the controller 302 predicts the temperature ofthe sump 222. To do so, in the illustrative embodiment, the controller302 performs at least one of blocks 526, 528. In block 526, thecontroller 302 (i.e., the sump temperature prediction module 404)predicts the temperature of the sump 222 as described in greater detailbelow with reference to FIG. 6. In block 528, the controller 302 (i.e.,the sump temperature prediction module 406) predicts the temperature ofthe sump 222 as described in greater detail below with reference to FIG.6.

From block 524, the illustrative method 500 subsequently proceeds toblock 530. In block 530, the controller 302 manages the temperature ofthe sump 222 based on the input data received in block 502 and the sumptemperature predicted in block 524. To do so, the controller 302performs block 532. In block 532, the controller 302 selectively enablesand disables cooling of the sump 222 by the cooling system 202 based onthe input data received in block 502 and the sump temperature predictedin block 524.

Referring now to FIG. 6, an illustrative method 600 of operating thetransmission system 200 may be embodied as, or otherwise include, a setof instructions that are executable by the control system 300 (i.e., thesump temperature management and cooling system control module 402 inconjunction with at least one of the sump temperature prediction modules404, 406). The method 600 corresponds to, or is otherwise associatedwith, performance of the blocks described below in the illustrativesequence of FIG. 6. It should be appreciated, however, that the method600 may be performed in one or more sequences different from theillustrative sequence.

The illustrative method 600 begins with block 602. In block 602, thecontroller 302 determines the current temperature of the sump 222 basedon the temperature input data provided by the sump temperature sensingdevice 336. From block 602, the method 600 subsequently proceeds toblock 604.

In block 604 of the illustrative method 600, the controller 302determines whether the measured temperature of the sump 222 is below areference threshold. It should be appreciated that in at least someembodiments, the reference threshold may correspond to, or otherwise beassociated with, a low temperature value substantially below anacceptable operating temperature for transmission oil stored in the sump222. In some embodiments, the reference threshold may be approximately20 degrees Celsius. In response to a determination by the controller 302that the measured temperature of the sump 222 is below the referencethreshold, the method 600 subsequently proceeds to block 606.

In block 606 of the illustrative method 600, the controller 302 outputsa signal to prevent use of the cooling system 202 to cool the sump 222.To do so, the controller 302 may output a signal to an output device(e.g., at least one of the fan activation relay 334 and the thermostat338) to disable cooling of the sump 222 by the heat exchanger 204.

Returning to block 604, if the controller 302 determines in block 604that the measured temperature of the sump 222 is not below the referencethreshold, the method 600 subsequently proceeds to block 608. In block608, the controller 302 outputs a signal to enable use of the coolingsystem 202 to cool the sump 222. To do so, the controller 302 may outputa signal to an output device (e.g., at least one of the fan activationrelay 334 and the thermostat 338) to enable cooling of the sump 222 bythe heat exchanger 204. In any case, from block 608, the method 600subsequently proceeds to block 610.

In block 610 of the illustrative method 600, the controller 302 (e.g.,at least one of the sump temperature prediction modules 404, 406)executes a sump temperature prediction scheme. To do so, in theillustrative embodiment, the controller 302 predicts a temperatureT_(predict) in the sump 222 based on a current sump temperature T_(n)(i.e., as measured by the sump temperature sensing device 336), apredicted rate of change in sump temperature Δ_(temp) (which may bereferred to as the gradient of the measured sump temperature), and aprediction time interval t_(horizon). More specifically, the controller302 predicts the temperature T_(predict) in the sump 222 according tothe following equation:

T _(predict) =T _(n)+(Δtemp*t _(horizon))  (1)

Additionally, in block 610 of the illustrative method 600, thecontroller 302 predicts the rate of change in sump temperature Δ_(temp)based on a previous predicted rate of change of sump temperature(Δ_(temp_previous)), the current sump temperature sample value (T_(n)),a previous sump temperature sample value (T₁-), a time measurement rate(t_(measurement_rate)), and a constant reference value (K_(filter)).More specifically, the controller 302 predicts the rate of change insump temperature Δ_(temp) according to the following equation:

Δ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter)  (2)

Further, in block 610 of the illustrative method 600, at least in someembodiments, the prediction time interval t_(horizon) may correspond to,or otherwise be associated with, one or more thirty second intervals.Additionally, in block 610, the current sump temperature sample value(T_(n)) and the previous sump temperature sample value (T_(n-1)) may bedetermined by the controller 302 over one or more one second timeintervals. It should be appreciated that the previous predicted rate ofchange of sump temperature (Δ_(temp_previous)) corresponds to, or isotherwise associated with, a previously executed iteration of theillustrative scheme for predicting the rate of change of sumptemperature Δ_(temp) by the controller 302.

Further still, in block 610 of the illustrative method 600, at least insome embodiments, the reference value (K_(filter)) is determined by thecontroller 302 based on ambient air temperature data (i.e., temperatureinput data provided by the ambient air temperature sensing device 326)and based on torque converter mode sensor data (i.e., mode data providedby the torque converter mode sensing device 328) and/or retarder inputdata (i.e., input data provided by the retarder sensing device 312). Insome embodiments, one or more control schemes or algorithms may beexecuted by the controller 302 to establish a relationship between theambient air temperature data and the mode data associated with thetorque converter 108 and/or the input data associated with the retarder.Based on that relationship, one or more lookup tables may be generatedand stored in the memory device 306 to define a range of constantreference values (K_(filter)). Therefore, each executed iteration of theillustrative scheme for predicting the rate of change of sumptemperature Δ_(temp) may include, or otherwise be embodied as, adetermination of the constant reference value (K_(filter)) by thecontroller 302 based on information contained in one or more lookuptables. In some embodiments (e.g., when the torque converter 108 isdetermined to be on or active based on the input data provided by thesensing device 328), the constant reference value (K_(filter)) mayinclude, or otherwise be embodied as, a programmable value that isestablished based on one or more operational characteristics of thetorque converter 108. Additionally, in some embodiments (e.g., when theretarder is determined to be on or active based on the input dataprovided by the sensing device 312), the constant reference value(K_(filter)) may include, or otherwise be embodied as, a programmablevalue that is established based on one or more operationalcharacteristics of the retarder. In some embodiments still, the constantreference value (K_(filter)) may include, or otherwise be embodied as, acalibrated value established by the user during execution of theillustrative scheme for predicting the rate of change of sumptemperature Δ_(temp) that is based on the state of the retarder (i.e.,as indicated by the sensing device 312) and the state of the torqueconverter 108 (i.e., as indicated by the sensing device 328).

Subsequent to the prediction of temperature T_(predict) in block 610,the illustrative method 600 proceeds to block 612. In block 612, thecontroller 302 makes multiple determinations. First, the controller 302determines, based on the input data received in block 502, whether theretarder is active based on the input provided by the retarder sensingdevice 312. Second, the controller 302 determines whether the enginebrake is active based on the input provided by the engine brake sensingdevice 314 in block 502. Third, the controller 302 determines whether afault state of the vehicle is present based on the input provided by theone or more fault diagnostic device(s) 316 in block 502. If thecontroller 302 determines in block 612 that the retarder is active, thatthe engine brake is active, or that a fault is present, the method 600subsequently proceeds to block 614. It should be appreciated that adetermination in block 612 that the retarder is active, that the enginebrake is active, or that a fault is present may coincide with, orotherwise represent, a determination of a heat-generating eventassociated with the transmission system 200 (e.g., the transmission 120)for which cooling is desired, as described below.

In block 614 of the illustrative method 600, the controller 302 outputsa signal to cool the sump 222 by the cooling system 202. To do so, thecontroller 302 may output a signal to an output device (e.g., at leastone of the fan activation relay 334 and the thermostat 338) to cool thesump 222 using the heat exchanger 204.

Returning to block 612 of the illustrative method 600, if the controller302 determines in block 612 that the retarder is inactive, that theengine brake is inactive, and that a fault is not present, the method600 subsequently proceeds to block 616. In block 616, the controller 302determines whether the predicted temperature T_(predict) of the sump 222is greater than a first temperature threshold. Additionally, in block616, the controller 302 determines whether the current measuredtemperature of the sump 222 T_(current) is greater than a secondtemperature threshold. At least in some embodiments, the firsttemperature threshold may correspond to, or otherwise be associatedwith, a predicted temperature limit of about 121° Celsius. Additionally,in at least some embodiments, the second temperature threshold maycorrespond to, or otherwise be associated with, a temperature of about115° Celsius. In any case, if the controller 302 determines in block 616that the predicted temperature T_(predict) of the sump 222 is greaterthan a first temperature threshold or that the current measuredtemperature of the sump 222 T_(current) is greater than a secondtemperature threshold, the method 600 subsequently proceeds to block 614in which the controller 302 cools the sump 222 by the heat exchanger204.

If the controller 302 determines in block 616 that the predictedtemperature T_(predict) of the sump 222 is not greater than a firsttemperature threshold and that the current measured temperature of thesump 222 T_(current) is not greater than a second temperature threshold,the method 600 subsequently proceeds to block 618. In block 618, thecontroller 302 determines whether the predicted temperature T_(predict)of the sump 222 is less than the first temperature threshold and whetherthe current measured temperature of the sump 222 T_(current) is lessthan a third temperature threshold. At least in some embodiments, thethird temperature threshold may correspond to, or otherwise beassociated with, a temperature of about 110° Celsius. In any case, ifthe controller 302 determines in block 616 that the predictedtemperature T_(predict) of the sump 222 is less than the firsttemperature threshold and that the current measured temperature of thesump 222 T_(current) is less than a third temperature threshold, themethod 600 subsequently proceeds to block 620.

In block 620 of the illustrative method 600, the controller 302 outputsa signal to disable cooling of the sump 222 by the cooling system 202.To do so, the controller 302 may output a signal to an output device(e.g., at least one of the fan activation relay 334 and the thermostat338) to disable cooling of the sump 222 by the heat exchanger 204.

Returning to block 618 of the illustrative method 600, if the controller302 determines in block 618 that the predicted temperature T_(predict)of the sump 222 is not less than the first temperature threshold andthat the current measured temperature of the sump 222 T_(current) is notless than the third temperature threshold, the method 600 subsequentlyproceeds to block 622. In block 622, the controller 302 maintains theoutput signal to one or more of the output devices to maintain theprevious states of the output devices.

Referring now to FIG. 7, a table 700 depicts possible states of variousdevices during performance of the method 600 as described above. In theillustrative table 700, column 702 depicts previous states of outputdevices, column 708 depicts states of various input devices, and column720 depicts next (i.e., determined with reference to previous) states ofoutput devices. In the illustrative table 700, column 702 includessub-columns 704 and 706, which correspond to previous states associatedwith the fan activation relay 344 and the thermostat 338, respectively.Column 708 includes sub-columns 710, 712, 714, 716, 718. Sub-column 710corresponds to the determinations made in block 612 of the method 600,sub-column 712 corresponds to the determination made in block 604 of themethod 600, sub-columns 714 and 716 correspond to the determinationsmade in block 616 of the method 600, and sub-column 718 corresponds tothe determinations made in block 618 of the method 600. Column 720includes sub-columns 722 and 724, which correspond to next statesassociated with the thermostat 338 and the fan activation relay 344,respectively.

In row 726 of the illustrative table 700, presuming a previous outputstate of the thermostat 338 to be off or inactive (i.e., as indicated incolumn 706), a determination is made by the controller 302 in block 604(i.e., as indicated by column 712) that the current measured temperatureof the sump 222 T_(current) is less than the reference threshold. As aresult, a signal is output to the thermostat 338 to turn on or activatethe thermostat (i.e., as indicated by column 722) and deactivate thecooling system 202 (i.e., as indicated by column 724 and block 606).

In row 728 of the illustrative table 700, presuming a previous outputstate of the thermostat 338 to be on or active (i.e., as indicated incolumn 706), a determination is made by the controller 302 in block 604(i.e., as indicated by column 712) that the current measured temperatureof the sump 222 T_(current) is less than the reference threshold. As aresult, a signal is output to the thermostat 338 to turn on or activatethe thermostat 338 (i.e., as indicated by column 722) and deactivate thecooling system 202 via the fan activation relay 334 (i.e., as indicatedby column 724 and block 606).

In row 730 of the illustrative table 700, presuming a previous outputstate of the thermostat 338 to be off or inactive (i.e., as indicated bycolumn 706) and a previous output state of the fan activation relay 334to be off or inactive (i.e., as indicated by column 704), and presuminga determination that the current measured temperature of the sump 222T_(current) is not less than the reference threshold (i.e., as indicatedin column 712), a determination is made by the controller 302 in block612 (i.e., as indicated by column 710) that the retarder is active, thatthe engine brake is active, or that a fault state is present. As aresult, a signal is output to the fan activation relay 334 to turn on oractivate the heat exchanger 204 (i.e., as indicated by column 724) anddeactivate the thermostat 338 (i.e., as indicated by column 722).

In row 732 of the illustrative table 700, presuming a previous outputstate of the thermostat 338 to be off or inactive (i.e., as indicated bycolumn 706) and a previous output state of the fan activation relay 334to be on or active (i.e., as indicated by column 704), and presuming adetermination that the current measured temperature of the sump 222T_(current) is not less than the reference threshold (i.e., as indicatedin column 712), a determination is made by the controller 302 in block612 (i.e., as indicated by column 710) that the retarder is active, thatthe engine brake is active, or that a fault state is present. As aresult, a signal is output to the fan activation relay 334 to turn on oractivate the heat exchanger 204 (i.e., as indicated by column 724) anddeactivate the thermostat 338 (i.e., as indicated by column 722).

In row 734 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be off or inactive (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), (iv) adetermination that the predicted temperature T_(predict) of the sump 222is not greater than the first temperature threshold (i.e., as indicatedin column 714), (v) a determination that the current measuredtemperature of the sump 222 T_(current) is not greater than the secondreference threshold (i.e., as indicated in column 716), and (vi) adetermination that the current measured temperature of the sump 222T_(current) is not less than the third temperature threshold (i.e., asindicated in column 718), the controller 302 maintains the signal outputto the thermostat 338 (i.e., as indicated in column 722) and to the fanactivation relay 334 (i.e., as indicated in column 724). As a result,the previous and next states of the thermostat 338 and the fanactivation relay 334 are the same in row 734.

In row 736 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be off or inactive (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), (iv) adetermination that the predicted temperature T_(predict) of the sump 222is not greater than the first temperature threshold (i.e., as indicatedin column 714), and (v) a determination that the current measuredtemperature of the sump 222 T_(current) is less than the thirdtemperature threshold (i.e., as indicated in column 718), the controller302 outputs a signal to turn off or deactivate the fan activation relay334 (i.e., as indicated by column 724). As a result, the previous andnext states of the thermostat 338 and the fan activation relay 334 arethe same in row 736.

In row 738 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be off or inactive (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), and (iv) adetermination that the current measured temperature of the sump 222T_(current) is greater than the second temperature threshold (i.e., asindicated in column 716), the controller 302 outputs a signal to turn onor activate the fan activation relay 334 (i.e., as indicated in column724). As a result, the controller 302 cools the sump 222 by the coolingsystem 202.

In row 740 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be off or inactive (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), and (iv) adetermination that the predicted temperature T_(predict) of the sump 222is greater than the first temperature threshold, the controller 302outputs a signal to turn on or activate the fan activation relay 334(i.e., as indicated in column 724). As a result, the controller 302cools the sump 222 by the cooling system 202.

In row 742 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be on or active (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), (iv) adetermination that the predicted temperature T_(predict) of the sump 222is not greater than the first temperature threshold (i.e., as indicatedin column 714), (v) a determination that the current measuredtemperature of the sump 222 T_(current) is not greater than the secondreference threshold (i.e., as indicated in column 716), and (vi) adetermination that the current measured temperature of the sump 222T_(current) is not less than the third temperature threshold (i.e., asindicated in column 718), the controller 302 maintains the signal outputto the thermostat 338 (i.e., as indicated in column 722) and to the fanactivation relay 334 (i.e., as indicated in column 724). As a result,the previous and next states of the thermostat 338 and the fanactivation relay 334 are the same in row 742.

In row 744 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be on or active (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), (iv) adetermination that the predicted temperature T_(predict) of the sump 222is not greater than the first temperature threshold (i.e., as indicatedin column 714), and (v) a determination that the current measuredtemperature of the sump 222 T_(current) is less than the thirdtemperature threshold (i.e., as indicated in column 718), the controller302 outputs a signal to turn off or deactivate the fan activation relay334 (i.e., as indicated by column 724). As a result, the controller 302disables cooling of the sump 222 by the cooling system 202.

In row 746 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be on or active (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), and (iv) adetermination that the current measured temperature of the sump 222T_(current) is greater than the second temperature threshold (i.e., asindicated in column 716), the controller 302 outputs a signal to turn onor activate the fan activation relay 334 (i.e., as indicated in column724). As a result, the controller 302 cools the sump 222 by the coolingsystem 202.

In row 748 of the illustrative table 700, presuming (i) a previousoutput state of the thermostat 338 to be off or inactive (i.e., asindicated by column 706) and a previous output state of the fanactivation relay 334 to be on or active (i.e., as indicated by column704), (ii) a determination that the retarder is not active, that theengine brake is not active, and that no faults are present (i.e., asindicated in column 710), (iii) a determination that the currentmeasured temperature of the sump 222 T_(current) is not less than thereference threshold (i.e., as indicated in column 712), and (iv) adetermination that the predicted temperature T_(predict) of the sump 222is greater than the first temperature threshold, the controller 302outputs a signal to turn on or activate the fan activation relay 334(i.e., as indicated in column 724). As a result, the controller 302cools the sump 222 by the cooling system 202.

Referring now to FIG. 8, an illustrative method 800 of operating thetransmission system 200 may be embodied as, or otherwise include, a setof instructions that are executable by the control system 300 (i.e., oneof the sump temperature prediction modules 404, 406, the brakingdetection module 408, and the transmission diagnostic control module410). For clarity and ease of illustration, the method 800 is depicteddiagrammatically as a block diagram that may be performed in one or moresequences.

In the illustrative method 800, in block 802, the controller 302executes the sump temperature prediction scheme associated with block610 based on, among other things, the current measured temperatureT_(current) of the sump 222. Following execution of the predictionscheme associated with block 610, the predicted temperature T_(predict)of the sump 222 is determined by the controller 302.

In block 804 of the illustrative method 800, the controller 302 comparesthe predicted temperature T_(predict) of the sump 222 to one or morereference hysteresis values that may be characterized by, or otherwiseaccount for, lag, delay, and/or history dependence of the predictedtemperature T_(predict) of the sump 222 during operation of thetransmission system 200. In at least some embodiments, the one or morereference hysteresis values associated with block 804 may include, orotherwise be embodied as, a low temperature threshold value of about110° Celsius. Additionally, in at least some embodiments, the one ormore reference hysteresis values associated with block 804 may include,or otherwise be embodied as, a high temperature threshold value of about115° Celsius. In any case, following the comparison made in block 804, afirst signal or request 806 is provided to an OR logic block 820.

In block 808 of the illustrative method 800, the controller 302 comparesthe current measured temperature T_(current) of the sump 222 to one ormore reference hysteresis values that may be characterized by, orotherwise account for, lag, delay, and/or history dependence of thepredicted temperature T_(predict) of the sump 222 during operation ofthe transmission system 200. In at least some embodiments, the one ormore reference hysteresis values associated with block 808 may include,or otherwise be embodied as, a low temperature threshold value of about110° Celsius. Additionally, in at least some embodiments, the one ormore reference hysteresis values associated with block 808 may include,or otherwise be embodied as, a high temperature threshold value of about115° Celsius. In any case, following the comparison made in block 808, asecond signal or request 810 is provided to the OR logic block 820.

In the illustrative method 800, the braking detection module 408provides a third signal or request 812 to the OR logic block 820. Itshould be appreciated that the request 812 provided by the brakingdetection module 408 may be based on, and may account for, the retarderinput provided by the retarder sensing device 312, the engine brakeinput provided by the engine brake sensing device 314, and the servicebrake input provided by the service brake sensing device 310.Furthermore, it should be appreciated that the input provided by theretarder sensing device 312 may indicate an activated or de-activatedstate of the retarder that is associated with one or more activation orde-activation sources.

The illustrative braking detection module 408, at least in someembodiments, may improve performance of the retarder (e.g., permit theretarder to convert increased kinetic energy to heat) and therebyincrease the braking capability of the vehicle compared to otherconfigurations. As a consequence of performance of the method 800 by thecontroller 302, activation of the fan(s) 206 of the cooling system 202during braking of the vehicle (e.g., using the retarder, the enginebrake, and/or the service brake) may be associated with, or otherwisecharacterized by, an increased energy demand that further facilitatesbraking. Presuming cooling of the sump 222 and the oil stored therein bythe cooling system 202 during each instance of braking, a lower averageresulting temperature of the sump 222 may provide, or otherwise beassociated with, a decreased energy demand (e.g., decreased energy foractivating the fan(s) 206) and thereby a fuel-savings benefit, at leastcompared to other configurations.

In the illustrative method 800, the transmission diagnostic module 410provides a fourth signal or request 814 to the OR logic block 820. Itshould be appreciated that the request 814 may be based on, and mayaccount for, the fault diagnostic input provided by the one or morefault diagnostic devices 316.

In the OR logic block 820 of the illustrative method 800, the controller302 receives the first, second, third, and fourth signals 806, 810, 812,814 and performs one or more actions based thereon. In one example, ifthe predicted temperature T_(predict) of the sump 222 is at or above ahigh temperature threshold (e.g., a high temperature hysteresis valueassociated with block 804) as indicated by the signal 806, thecontroller 302 activates the fan activation relay 334 to enable coolingof the sump 222 by the cooling system 202. In another example, if thecurrent measured temperature T_(current) of the sump 222 is at or abovea high temperature threshold (e.g., a high temperature hysteresis valueassociated with block 808) as indicated by the signal 810, thecontroller 302 activates the fan activation relay 334 to enable coolingof the sump 222 by the cooling system 202. In yet another example, ifthe braking input (e.g., the input indicated by the signal 812) isindicative of engagement or activation of the retarder, the enginebrake, and/or the service brake of the vehicle, the controller 302activates the fan activation relay 334 to enable cooling of the sump 222by the cooling system 202. In yet another example still, if the faultdiagnostic input (e.g., the input indicated by the signal 814) isindicative of a fault state of the vehicle and/or the transmissionsystem 200, the controller 302 activates the fan activation relay 334 toenable cooling of the sump 222 by the cooling system 202. In each one ofthe aforementioned examples in which the controller 302 enables coolingvia the cooling system 202, a signal or request 830 output from the ORlogic block 820 includes, or is otherwise embodied as, a request toactivate the fan activation relay 334 and thereby cool the sump 222 viathe cooling system 202.

It should be appreciated that, if the controller 302 in OR logic block820 determines that (i) the predicted temperature T_(predict) of thesump 222 is not at or above the high temperature threshold, (ii) thecurrent measured temperature T_(current) of the sump 222 is not at orabove the high temperature threshold, (iii) no braking input indicativeof activation of the retarder, the engine brake, and/or the servicebrake has been provided, and (iv) no input indicative of a fault stateof the vehicle and/or the transmission system 200 has been provided, thesignal 830 output from the OR logic block 820 includes, or is otherwiseembodied as, a request to de-activate (or maintain deactivation of) therelay 334 to turn off the heat exchanger 204 and prevent cooling via thecooling system 202. Regardless, in the illustrative method 800, thesignal 830 output from the OR logic block 820, as well as the currentmeasured temperature T_(current) of the sump 222, are provided to block832.

In block 832 of the illustrative method 800, the controller 302 executeslow temperature logic based on the current measured temperatureT_(current) of the sump 222. In one example, in the event that thesignal 830 includes, or is otherwise embodied as, a request to activatethe fan activation relay 334 and thereby cool the sump 222 via thecooling system 202, the controller 302 may block activation of thecooling system 202 if the controller 302 determines that the currentmeasured temperature T_(current) of the sump 222 is less than areference threshold (e.g., the reference threshold associated with block604 of the method 600). In that example, activation of the coolingsystem 202 may be blocked due to, or may be blocked as a consequence of,activation of the thermostat 338. It should be appreciated that the lowtemperature logic executed in block 832 may be substantially similar tothe logic associated with blocks 604 and 606 of the illustrative method600. In any case, following completion of block 832, a signal 834 isoutput from the block 832.

Referring now to FIG. 9, at least in some embodiments, the controller302 may be communicatively coupled to the cooling system 202 via adirect (e.g., hardwired) connection. In such embodiments, the controller302 may control operation of the fan activation relay 334, the primaryfan 208, and/or the one or more supplemental fans 210 by pulse widthmodulation as indicated by block 902. In other embodiments, thecontroller 302 may be communicatively coupled to the cooling system 202via a controller area network (CAN). In such embodiments, the controller302 may control operation of the fan activation relay 334, the primaryfan 208, and/or the one or more supplemental fans 210 by a CAN requestas indicated by block 904.

Referring now to FIG. 10, an illustrative method 1000 of operating thetransmission system 200 may be embodied as, or otherwise include, a setof instructions that are executable by the control system 300 (i.e., thesump temperature management and cooling system control module 402 inconjunction with at least one of the sump temperature prediction modules404, 406). The method 1000 corresponds to, or is otherwise associatedwith, performance of the blocks described below in the illustrativesequence of FIG. 10. It should be appreciated, however, that the method1000 may be performed in one or more sequences different from theillustrative sequence.

The illustrative method 1000 begins with block 1002. In block 1002,presuming that cooling of the sump 222 by the cooling system 202 isenabled, the controller 302 controls the primary fan 208 to cool thesump 222 by the heat exchanger 204. To do so, the controller 302 mayperform at least one of blocks 1004 and 1006. In block 1004, thecontroller 302 controls the primary fan 208 by pulse width modulationcontrol (e.g., as indicated by block 902). In block 1006, the controller302 controls the primary fan 208 by a CAN request (e.g., as indicated byblock 904). In any case, from block 1002, the method 1000 subsequentlyproceeds to block 1008.

In block 1008 of the illustrative method 1000, presuming that cooling ofthe sump 222 by the cooling system 202 is enabled, the controller 302controls the one or more supplemental fans 210 to deliver additionalcooling by the heat exchanger 204. To do so, the controller 302 mayperform at least one of blocks 1010 and 1012. In block 1010, thecontroller 302 controls the one or more supplemental fans 210 by pulsewidth modulation control (e.g., as indicated by block 902). In block1012, the controller 302 controls the one or more supplemental fans 210by a CAN request (e.g., as indicated by block 904).

Referring now to FIG. 11, an illustrative diagram 1100 depictscommunication between the controller 302 and the cooling system 202 inuse of the transmission system 200 (e.g., during performance of themethod 600). At least in some embodiments, the operations describedbelow may be performed by at least one of the sump temperatureprediction modules 404, 406 during performance of the method 600.

In the illustrative embodiment, a target sump temperature 1102 and ameasured sump temperature 1104 are provided as inputs to the controller302. It should be appreciated that in at least some embodiments, thetarget sump temperature 1102 may be determined based on, among otherthings, the current measured temperature T_(current) of the sump 222(i.e., as indicated by the sump temperature sensing device 336) and/orthe predicted temperature T_(predict) of the sump 222. Additionally, inat least some embodiments, the target sump temperature 1102 may bedetermined based on, among other things, input provided by an operatorand/or one or more lookup tables stored in the memory 306 of thecontroller 302. In any case, in the illustrative embodiment, themeasured sump temperature 1104 is determined based on the currentmeasured temperature T_(current) of the sump 222.

In block 1106 of the illustrative diagram 1100,proportional-integral-derivative (PID) control is performed by thecontroller 302 based on the target sump temperature 1102 and themeasured sump temperature 1104. At least in some embodiments, PIDcontrol performed in block 1106 may include, or otherwise be embodiedas, calculation of an error value based on the difference between thetarget sump temperature 1102 and the measured sump temperature 1104 andcorrection and/or adjustment of the calculated error value based on oneor more terms or coefficients (e.g., a proportional term, an integralterm, and a derivative term). In such embodiments, those terms orcoefficients may be affected by, or determined based on, the currentmeasured temperature T_(current) of the sump 222 and the measuredambient air temperature (i.e., based on the input from the ambient airtemperature sensing device 326), among other things.

In block 1108 of the illustrative diagram 1100, braking activity logicmay be performed by the controller 302 (e.g., the braking detectionmodule 408) substantially contemporaneously, and/or in parallel with,the performance of PID control in block 1106. It should be appreciatedthat performance of the braking activity logic in block 1108 mayinclude, or otherwise be embodied as, receipt of braking inputassociated with the retarder, the engine brake, and the service brake ofthe vehicle (i.e., from the retarder sensing device 312, the enginebrake sensing device 314, and the service brake sensing device 310,respectively).

In block 1110 of the illustrative diagram 1100, outputs from the PIDcontrol block 1106 and the braking activity logic block 1108 areprovided as inputs. In the illustrative embodiment, any braking activity(e.g., activation of one or more of the retarder, the engine brake, andthe service brake) determined following performance of block 1108results in, or otherwise associated with, a maximum or 100% activationsignal provided as a CAN request 1112 to the cooling system 202following performance of block 1110. That is, any braking activityresults in, or otherwise associated with, a CAN request to providemaximum cooling via the cooling system 202. It should be appreciated,however, that in the event no braking activity is determined followingperformance of block 1108, another activation signal may be provided asCAN request 1112 to the cooling system 202 that corresponds to, or isotherwise associated with, less cooling (i.e., <100% cooling) by thecooling system 202. Therefore, in the illustrative embodiment, via theCAN request 1112, the controller 302 is configured to provide a fanactivation signal to achieve continuous percentage control (e.g., anypercentage between 0-100% of maximum cooling) of cooling by the coolingsystem 202.

While the disclosure has been illustrated and described in detail in theforegoing drawings and description, the same is to be considered asexemplary and not restrictive in character, it being understood thatonly illustrative embodiments thereof have been shown and described andthat all changes and modifications that come within the spirit of thedisclosure are desired to be protected.

1. A transmission system for a vehicle, the transmission systemcomprising: a transmission configured to receive rotational powersupplied by a drive unit and provide the rotational power to a load inuse of the transmission system; and a heat exchanger fluidly coupled tothe transmission and configured to cool a sump of the transmission tomanage transmission oil temperature in use of the transmission system,wherein the transmission includes a control system having a plurality ofsensors and a controller coupled to the plurality of sensors that has aprocessor and a memory device coupled to the processor, wherein at leastone of the plurality of sensors is configured to provide sensor dataindicative of a state of a braking device of the vehicle or a faultstate of the vehicle, and wherein the memory device has instructionsstored therein that are executable by the processor to cause theprocessor to receive the sensor data from the at least one of theplurality of sensors and to control operation of the heat exchanger toselectively cool the sump by the heat exchanger based on the sensor datato promote fuel economy in use of the transmission system.
 2. Thetransmission system of claim 1, wherein the plurality of sensors includea first brake sensor configured to provide brake sensor data indicativeof a state of a first braking device of the vehicle and a faultdiagnostic sensor configured to provide fault diagnostic data indicativeof a fault state of the vehicle, and wherein the instructions stored inthe memory device are executable by the processor to cause the processorto receive the brake sensor data from the first brake sensor and thefault diagnostic data from the fault diagnostic sensor and toselectively cool the sump by the heat exchanger based on the brakesensor data and the fault diagnostic data.
 3. The transmission system ofclaim 2, wherein the brake sensor data from the first brake sensor isindicative of a state of a retarder of the vehicle, wherein theplurality of sensors includes a second brake sensor configured toprovide brake sensor data indicative of a state of an engine brake ofthe vehicle, and wherein the instructions stored in the memory deviceare executable by the processor to cause the processor to: receive thebrake sensor data from the first and second brake sensors and the faultdiagnostic data from the fault diagnostic sensor; determine whether theretarder is active based on the brake sensor input from the first brakesensor; determine whether the engine brake is active based on the brakesensor input from the second brake sensor; determine whether a fault ispresent based on the fault diagnostic data from the fault diagnosticsensor; and cool the sump by the heat exchanger in response to adetermination that the retarder is active, that the engine brake isactive, or that a fault is present.
 4. The transmission system of claim3, wherein the instructions stored in the memory device are executableby the processor to cause the processor to, in response to adetermination that the retarder is inactive, that the engine brake isinactive, and that a fault is not present, determine whether a predictedtemperature of the sump is greater than a first temperature threshold orwhether a current temperature of the sump is greater than a secondtemperature threshold, and to cool the sump by the heat exchanger inresponse to a determination that the predicted temperature of the sumpis greater than the first temperature threshold or a determination thatthe current temperature of the sump is greater than the secondtemperature threshold.
 5. The transmission system of claim 4, whereinthe instructions stored in the memory device are executable by theprocessor to cause the processor to, in response to determination thatthe predicted temperature of the sump is not greater than the firsttemperature threshold and a determination that the current temperatureof the sump is not greater than the second temperature threshold,determine whether the predicted temperature of the sump is less than thefirst temperature threshold and whether the current temperature of thesump is less than a third temperature threshold, and to disable coolingof the sump by the heat exchanger in response to a determination thatthe predicted temperature of the sump is less than the first temperaturethreshold and the current temperature of the sump is less than the thirdtemperature threshold.
 6. The transmission system of claim 1, whereinthe instructions stored in the memory device are executable by theprocessor to cause the processor to selectively cool the sump based on apredicted temperature of the sump in use of the transmission system. 7.The transmission system of claim 6, wherein the instructions stored inthe memory device are executable by the processor to cause the processorto predict the sump temperature based on a predicted rate of change insump temperature (Δ_(temp)) multiplied by a prediction time interval(t_(horizon)) and summed with a current sump temperature value (T_(n)).8. The transmission system of claim 7, wherein the instructions storedin the memory device are executable by the processor to cause theprocessor to predict the rate of change in sump temperature (Δ_(temp))based on a previous predicted rate of change of sump temperature(Δ_(temp_previous)), the current sump temperature sample value (T_(n)),a previous sump temperature sample value (T_(n-1)), a time measurementrate (t_(measurement_rate)), and a constant reference value(K_(filter)), and wherein the instructions stored in the memory deviceare executable by the processor to cause the processor to predict therate of change in sump temperature (Δ_(temp)) according to the equationΔ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter).
 9. The transmissionsystem of claim 8, wherein the instructions stored in the memory deviceare executable by the processor to cause the processor to determine theconstant reference value (K_(filter)) based on temperature sensor dataindicative of an ambient air temperature and based on mode sensor dataindicative of an operational mode of a torque converter or a retarder.10. The transmission system of claim 8, wherein the instructions storedin the memory device are executable by the processor to cause theprocessor to determine the current sump temperature sample value (T_(n))and the previous sump temperature sample value (T_(n-1)) over one secondtime intervals and to determine the prediction time interval(t_(horizon)) over thirty second intervals.
 11. The transmission systemof claim 1, wherein the instructions stored in the memory device areexecutable by the processor to cause the processor to: receive brakesensor data from a first brake sensor indicative of a state of aretarder of the vehicle; receive brake sensor data from a second brakesensor indicative of a state of an engine brake of the vehicle; receivebrake sensor data from a third brake sensor indicative of a state of aservice brake of the vehicle; receive fault data from a fault diagnosticsensor indicative of a fault state of the vehicle; receive grade datafrom an inclinometer indicative of a grade of a surface on which thevehicle is positioned; receive accelerator data from an acceleratorsensor indicative of depression of an accelerator pedal of the vehicle;receive temperature data from an air temperature sensor indicative ofthe ambient air temperature; receive input provided by an operator;receive mode sensor data from a torque converter sensor indicative of anoperational mode of a torque converter; and selectively cool the sump bythe heat exchanger based on the brake sensor data from the first,second, and third brake sensors, the fault data, the grade data, theaccelerator data, the temperature data, the input provided by theoperator, and the mode sensor data.
 12. A control system for a vehiclethat includes a transmission configured to receive rotational powersupplied by a drive unit and provide the rotational power to a load anda heat exchanger fluidly coupled to the transmission and configured tocool a sump of the transmission to manage transmission oil temperature,the control system comprising: a first brake sensor configured toprovide brake sensor data indicative of a state of a first brakingdevice of the vehicle; a fault diagnostic sensor configured to providefault diagnostic data indicative of a fault state of the vehicle; and acontroller communicatively coupled to the first brake sensor and thefault diagnostic sensor, wherein the controller includes a memory devicehaving instructions stored therein that are executable by a processor tocause the processor to receive the brake sensor data from the firstbrake sensor and the fault diagnostic data from the fault diagnosticsensor and to selectively cool the sump by the heat exchanger based onthe brake sensor data and the fault diagnostic data to promote fueleconomy in use of the transmission system.
 13. The control system ofclaim 12, further comprising a second brake sensor configured to providebrake sensor data indicative of a state of a second braking device ofthe device, wherein the instructions stored in the memory are executableby the processor to cause the processor to: receive the brake sensordata from the first and second brake sensors and the fault diagnosticdata from the fault diagnostic sensor; determine whether a retarder ofthe vehicle is active based on the brake sensor data from the firstbrake sensor; determine whether an engine brake of the vehicle is activebased on the brake sensor data from the second brake sensor; determinewhether a fault is present based on the fault diagnostic data from thefault diagnostic sensor; and cool the sump by the heat exchanger inresponse to a determination that the retarder is active, that the enginebrake is active, or that a fault is present.
 14. The control system ofclaim 13, wherein the instructions stored in the memory device areexecutable by the processor to cause the processor to, in response to adetermination that the retarder is inactive, that the engine brake isinactive, and that a fault is not present, determine whether a predictedtemperature of the sump is greater than a first temperature threshold orwhether a current temperature of the sump is greater than a secondtemperature threshold, and to cool the sump by the heat exchanger inresponse to a determination that the predicted temperature of the sumpis greater than the first temperature threshold or a determination thatthe current temperature of the sump is greater than the secondtemperature threshold.
 15. The control system of claim 14, wherein theinstructions stored in the memory device are executable by the processorto cause the processor to, in response to a determination that thepredicted temperature of the sump is not greater than the firsttemperature threshold and a determination that the current temperatureof the sump is not greater than the second temperature threshold,determine whether the predicted temperature of the sump is less than thefirst temperature threshold and whether the current temperature of thesump is less than a third temperature threshold, and to disable coolingof the sump by the heat exchanger in response to a determination thatthe predicted temperature of the sump is less than the first temperaturethreshold and the current temperature of the sump is less than the thirdtemperature threshold.
 16. The control system of claim 12, wherein theinstructions stored in the memory device are executable by the processorto cause the processor to: selectively cool the sump based on apredicted temperature of the sump in use of the transmission system;predict the sump temperature based on a predicted rate of change in sumptemperature (Δ_(temp)) multiplied by a prediction time interval(t_(horizon)) and summed with a current sump temperature value (T_(n));and predict the rate of change in sump temperature (Δ_(temp)) based on aprevious predicted rate of change of sump temperature(Δ_(temp_previous)), the current sump temperature sample value (T_(n)),a previous sump temperature sample value (T_(n-1)), a time measurementrate (t_(measurement_rate)), and a constant reference value (K_(filter))according to the equationΔ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter).
 17. A method ofoperating a vehicle that includes a transmission configured to receiverotational power supplied by a drive unit and provide the rotationalpower to a load and a heat exchanger fluidly coupled to the transmissionand configured to cool a sump of the transmission to manage transmissionoil temperature, the method comprising: receiving, by a controller ofthe transmission system, brake sensor data provided by a first brakesensor of the transmission system that is indicative of a state of afirst braking device of the vehicle; receiving, by the controller, faultdiagnostic data provided by a fault diagnostic sensor of thetransmission system that is indicative of a fault state of the vehicle;and selectively cooling, by the controller using the heat exchanger, thesump based on the brake sensor data and the fault diagnostic data topromote fuel economy in use of the transmission system.
 18. The methodof claim 17, further comprising: receiving, by the controller, brakesensor data provided by a second brake sensor of the transmission systemthat is indicative of a state of a second braking device of the vehicle;determining, by the controller, whether a retarder of the vehicle isactive based on the brake sensor input data the first brake sensor;determining, by the controller, whether an engine brake of the vehicleis active based on the brake sensor data from the second brake sensor;determining, by the controller, whether a fault is present based on thefault diagnostic data from the fault diagnostic sensor; and cooling, bythe controller using the heat exchanger, the sump in response to adetermination that the retarder is active, that the engine brake isactive, or that a fault is present.
 19. The method of claim 18, furthercomprising: determining, by the controller in response to adetermination that the retarder is inactive, that the engine brake isinactive, or that a fault is not present, whether a predictedtemperature of the sump is greater than a first temperature threshold orwhether a current temperature of the sump is greater than a secondtemperature threshold; and cooling, by the controller using the heatexchanger, the sump in response to a determination that the predictedtemperature of the sump is greater than the first temperature thresholdor a determination that the current temperature of the sump is greaterthan the second temperature threshold.
 20. The method of claim 17,further comprising: selectively cooling, by the controller using theheat exchanger, the sump based on a predicted temperature of the sump inuse of the transmission system; predicting, by the controller, the sumptemperature based on a predicted rate of change in sump temperature(Δ_(temp)) multiplied by a prediction time interval (t_(horizon)) andsummed with a current sump temperature value (T_(n)); and predicting, bythe controller, the rate of change in sump temperature (Δ_(temp)) basedon a previous predicted rate of change of sump temperature(Δ_(temp_previous)), the current sump temperature sample value (T_(n)),a previous sump temperature sample value (T_(n-1)), a time measurementrate (t_(measurement_rate)), and a constant reference value (K_(filter))according to the equationΔ_(temp)=Δ_(temp_previous)+([T _(n) −T _(n-1)]/t_(measurement_rate)−Δ_(temp_previous))/K _(filter).